Disparities in Socioeconomic Factors Mediate the Impact of Racial Segregation Among Patients With Hepatopancreaticobiliary Cancer

BACKGROUND

Structural racism within the U.S. health care system contributes to disparities in oncologic care. This study sought to examine the socioeconomic factors that underlie the impact of racial segregation on hepatopancreaticobiliary (HPB) cancer inequities.

METHODS

Both Black and White patients who presented with HPB cancer were identified from the linked Surveillance, Epidemiology, and End Results (SEER)-Medicare database (2005-2015) and 2010 Census data. The Index of Dissimilarity (IoD), a validated measure of segregation, was examined relative to cancer stage at diagnosis, surgical resection, and overall mortality. Principal component analysis and structural equation modeling were used to determine the mediating effect of socioeconomic factors.

RESULTS

Among 39,063 patients, 86.4 % (n = 33,749) were White and 13.6 % (n = 5314) were Black. Black patients were more likely to reside in segregated areas than White patients (IoD, 0.62 vs. 0.52; p < 0.05). Black patients in highly segregated areas were less likely to present with early-stage disease (relative risk [RR], 0.89; 95 % confidence interval [CI] 0.82-0.95) or undergo surgery for localized disease (RR, 0.81; 95% CI 0.70-0.91), and had greater mortality hazards (hazard ratio 1.12, 95% CI 1.06-1.17) than White patients in low segregation areas (all p < 0.05). Mediation analysis identified poverty, lack of insurance, education level, crowded living conditions, commute time, and supportive income as contributing to 25 % of the disparities in early-stage presentation. Average income, house price, and income mobility explained 17 % of the disparities in surgical resection. Notably, average income, house price, and income mobility mediated 59 % of the effect that racial segregation had on long-term survival.

CONCLUSION

Racial segregation, mediated through underlying socioeconomic factors, accounted for marked disparities in access to surgical care and outcomes for patients with HPB cancer.

HIF-1α -1790G>A polymorphism significantly increases the risk of digestive tract cancer: A meta-analysis

AIM: To investigate the association between hypoxia-inducible factor-1α (HIF-1α) polymorphisms (-1772C>T and -1790G>A) and the risk of digestive tract cancer.

METHODS: A total of 13 eligible studies were retrieved from PubMed, EMBASE, and the China National Knowledge Infrastructure database. The odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to estimate the strength of the associations.

RESULTS: By pooling the eligible studies, we found that the HIF-1α -1772C>T polymorphism was not associated with the risk of developing digestive tract cancer (dominant comparison, OR: 1.156; 95%CI: 0.839-1.593; P_{heterogeneity} = 0.007), and no significant association was found in the Asian population or the Caucasian population. However, for the -1790G>A polymorphism, carriers of the variant -1790A allele had a significantly increased risk of digestive tract cancer compared with those with the wildtype -1790G allele (dominant comparison, OR: 3.252; 95%CI: 1.661-6.368; P_{heterogeneity} < 0.001). Additionally, this increased risk of digestive cancer was only detected in Asians; there was no significant association in Caucasians.

CONCLUSION: This meta-analysis demonstrates that the HIF-1α -1790G>A polymorphism is associated with a significantly increased risk of digestive tract cancer, while the -1772C>T polymorphism is not.

TNF-α-308 polymorphism and risk of digestive system cancers: A meta-analysis

AIM: To evaluate the association between the tumour necrosis factor alpha-308 (TNF-α-308) gene polymorphism and the risk of digestive system cancers.

METHODS: All eligible case-control studies published up to December 2012 were identified by searching PubMed, Web of Science, Embase and China National Knowledge Internet without language restrictions. The risk of digestive system cancers associated with the TNF-α-308 polymorphism was estimated for each study using odds ratio (OR) together with its 95%CI, respectively. Cochrane Collaboration RevMan 5.1 was used to perform the analysis. A χ²-test-based Q statistic test and an I² test were performed to assess the between-study heterogeneity. When the Q test was significant (P < 0.05) or I² > 50%, the random effects model was used, otherwise the fixed effects model was used.

RESULTS: Fifty-eight studies from fifty-five publications with a total of 9986 cancer patients and 15511 healthy controls were included. Overall, a significant association was found between the TNF-α-308 polymorphism and the risk of digestive system cancers [dominant model: OR = 1.23, 95%CI: 1.09-1.39, (G/A) vs (G/G): OR = 1.15, 95%CI: 1.02-1.28, (A/A) vs (G/G): OR = 1.44, 95%CI: 1.19-1.73, recessive model: OR = 1.38, 95%CI: 1.15-1.66]. Furthermore, when the analysis was stratified by ethnicity, similar results were observed in both the Asian and Caucasian populations, except for the dominant model and heterozygote comparisons in the Asian population [dominant model: OR = 1.24, 95%CI: 0.99-1.56, (G/A) vs (G/G): OR = 1.09, 95%CI: 0.96-1.24]. When the cancer type subgroups were examined, similar results were detected in gastric and hepatocellular carcinomas; however, no significant association was observed among other digestive system cancers.

CONCLUSION: The TNF-α-308 gene polymorphism may be significantly associated with the risk of gastric and hepatocellular carcinomas, but not colorectal, pancreatic, or oesophageal cancer, in the Asian population.

Association of TLR2 and TLR4 polymorphisms with risk of cancer: a meta-analysis

BACKGROUNDS

The activation of Toll-like receptors (TLRs) may be an important event in the immune evasion of tumor cell. Recently, numerous studies have investigated the associations between TLR2 -196 to -174 del and two SNPs of TLR4 (rs4986790 and rs4986791) and the susceptibility to different types of cancer; however, the results remain conflicting. The aim of this study was to assess the association between TLR2 and TLR4 polymorphisms and cancer risk in a meta-analysis with eligible published studies.

METHODOLOGY/PRINCIPLE FINDINGS

A dataset composed of 14627 cases and 17438 controls from 34 publications were included in a meta-analysis to evaluate the association between overall cancer risk or cancer-specific risk and three SNPs of TLRs (TLR2 -196 to -174 del, TLR4 rs4986790 and rs4986791). The results showed that all of these three polymorphisms were significantly associated with the increased cancer risk (dominant model: OR = 1.64, 95% CI: 1.04-2.60 for TLR2 -196 to -174 del; OR = 1.19, 95% CI: 1.01-1.41 for TLR4 rs4986790; and OR = 1.47, 95% CI: 1.120-1.80 for TLR4 rs4986791; respectively). In stratified analysis, we found the effect of TLR2 -196 to -174 del on cancer risk remained significant in the subgroup of Caucasians and South Asians, but not in East Asians. However, the association between rs4986791 and cancer risk was significant in both South Asians and East Asians, but not in Caucasians. Furthermore, the association between rs4986790 and cancer risk was statistically significant in digestive cancers (dominant model: OR = 1.76, 95% CI: 1.13-2.73) and female-specific cancers (dominant model: OR = 1.50, 95% CI: 1.16-1.94). However, no significant association with risk of digestive system cancers was observed for TLR2 -196 to -174 del and TLR4 rs4986791.

CONCLUSIONS/SIGNIFICANCE

This meta-analysis presented additional evidence for the association between TLR2 and TLR4 polymorphisms and cancer risk. Further well-designed investigations with large sample sizes are required to confirm this conclusion.

The miR-146a rs2910164 G > C polymorphism and susceptibility to digestive cancer in Chinese

BACKGROUND

Several studies have reported the role of the miR-146a rs2910164 G > C polymorphism as a susceptibility factor for several digestive cancers. However, the results have been controversial. Therefore, we conducted the present meta-analysis to obtain the most reliable estimate of the association.

METHODS

PubMed, Embase and Web of Science databases were searched. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were extracted and pooled to assess the strength of the association between miR-146a rs2910164 G > C polymorphism and digestive cancer risk. A total of four eligible studies including 3,447 cases and 5,041 controls based on the search criteria were included.

RESULTS

We observed that miR-146a rs2910164 G > C polymorphism was not significantly correlated with digestive cancer risks when all studies were pooled into the meta-analysis. While we found that miR-146a rs2910164 polymorphism was not associated with gastric cancer, it was significantly linked with hepatocellular cancer risk (the homozygote codominant model: OR = 1.40, 95% CI = 1.04-1.87). In the stratified analysis by ethnicity, significant associations were observed in Chinese population for the allele contrast model (OR = 1.25; 95% CI = 1.12-1.38), for the homozygote codominant model (OR = 1.62; 95% CI = 1.28-2.04), and for the recessive model (OR = 1.38; 95% CI = 1.16-1.64). However, studies with Asian groups presented no significant association for all genetic models.

CONCLUSIONS

This meta-analysis suggests that the miR-146a rs2910164 G > C polymorphism is a low-penetrant risk factor for digestive cancers in Chinese.

A genetic variant in miR-196a2 increased digestive system cancer risks: a meta-analysis of 15 case-control studies

Background

MicroRNAs (miRNAs) negatively regulate the gene expression and act as tumor suppressors or oncogenes in oncogenesis. The association between single nucleotide polymorphism (SNP) in miR-196a2 rs11614913 and the susceptibility of digestive system cancers was inconsistent in previous studies.

Methodology/Principal Findings

An updated meta-analysis based on 15 independent case-control studies consisting of 4999 cancer patients and 7606 controls was performed to address this association. It was found that miR-196a2 polymorphism significantly elevated the risks of digestive system cancers (CT vs. TT, OR = 1.25, 95% CI = 1.07–1.45; CC vs. TT, OR = 1.38, 95% CI = 1.13–1.67; CC/CT vs. TT, OR = 1.29, 95% CI = 1.10–1.50; CC vs. CT/TT, OR = 1.14, 95% CI = 1.01–1.30; C vs. T, OR = 1.15, 95% CI = 1.05–1.26). We also found that variant in miR-196a2 increased the susceptibility of colorectal cancer (CRC) (CT vs. TT, OR = 1.23, 95% CI = 1.04–1.44; CC vs. TT, OR = 1.32, 95% CI = 1.08–1.61; CC/CT vs. TT, OR = 1.25, 95% CI = 1.07–1.46; C vs. T, OR = 1.15, 95% CI = 1.05–1.28), while the association in recessive model (CC vs. CT/TT, OR = 1.16, 95% CI = 0.98–1.38) showed a marginal significance. Additionally, significant association between miR-196a2 polymorphism and increased risk of hepatocellular cancer (HCC) was detected. By stratifying tumors on the basis of site of origin, source of controls, ethnicity and allele frequency in controls, elevated cancer risks were observed.

Conclusion/Significance

Our findings suggest the significant association between miR-196a2 polymorphism and increased susceptibility of digestive system cancers, especially of CRC, HCC and Asians. Besides, C allele may contribute to increased digestive cancer risks.

Is there disparity in the care of minority patients with upper aerodigestive tract malignancy?

The data presently available indicate that there is unequal (disparate) care in patients with head and neck cancer. The reasons for this are likely multifactorial and require further study. Complicating such work is the need for subgroup analysis. For example, Hispanics are not a homogeneous ethnic group; hence, differences in social perception, cultural mores, and available medical resources can be demonstrated that can directly impact care and outcome. Appropriate epidemiologic studies are needed with more underserved minority patients to analyze these differences further and to address such differences.

Middle digestive cancers in Texas Hispanics: a New World syndrome?

To test the hypothesis that middle digestive cancers in Texas Hispanics follow the patterns predicted by the New World Syndrome (1984), cancer incidence rates and relative risks for middle digestive cancers were estimated for 1944-1992. The relative risk for all middle digestive cancers is significantly elevated in Texas Hispanics compared with Anglos, and this risk has increased over time. Elevated risks of these cancers in Texas Hispanics have been explained as resulting from the evolutionary history of Native Americans (American Indians), their genetic relation to Texas Hispanics, and a changing diet and lifestyle. Recent Texas cancer incidence data add further support to the hypothesis. Other current disease prevalence data in Texas Hispanics, percent of the population which is diabetic and percent which is overweight, are also consistent with the New World Syndrome. Expected patterns of disease in males vs females are also confirmed. Factors that do not support the New World Syndrome hypothesis and can be examined by future studies are described. This is the first report since the original describing and updating patterns of middle digestive cancers in Texas Hispanics as resulting from the New World Syndrome. Application of these findings to contemporary medical practice and to cancer prevention are reviewed.

Cancer of the digestive system in Circumpolar Inuit

Cancer of the oesophagus, stomach, small intestine, colon, rectum, liver, gallbladder, biliary tract and pancreas was studied in the Inuit populations of Alaska, Canada and Greenland. Indirect standardization to the populations in Canada, Connecticut (USA) and Denmark was used. High risk of oesophageal cancer was observed in both sexes with standardized incidence ratios (SIRs) of up to 7. An increased risk of colon and rectum cancer occurred among Alaskan Inuit compared with the Inuit populations in Canada and Greenland, which had lower rates. Liver and gallbladder cancer rates were high, with SIRs of 1.5 to 4.1, whereas there were no differences in pancreatic cancer in the populations compared. Dietary habits, alcohol and tobacco consumption are believed to play an important role in most of the observed cancer patterns, but for liver cancer hepatitis B virus infection is also believed to have a causal role.

Increased mortality with gallstone disease: results of a 20-year population-based survey in Pima Indians

OBJECTIVE

To determine if gallstone disease is associated with an increased risk for malignancy and higher total mortality in Pima Indians.

DESIGN

Inception cohort.

SETTING

American Indian community.

PARTICIPANTS

Age- and sex-stratified random population-based sample.

MEASUREMENTS

Between 1966 and 1969, an age- and sex-stratified random sample of Pima Indians from the Gila River Indian Community in Arizona was examined to identify evidence of gallstone disease defined as either gallstones (oral cholecystography) or previous cholecystectomy. During 20 years of follow-up, deaths were recorded and underlying causes of death, according to death certificates, were determined.

RESULTS

Among 383 persons with known gallbladder status, 186 (49%) died: 133 among the 222 persons with gallstone disease and 53 among the 161 without. The overall death rate was higher in persons with gallstone disease than in those with normal gallbladders. The age- and sex-adjusted death rate ratio was 1.9 (95% Cl, 1.3 to 2.7). Furthermore, the death rate attributed to malignancies was 6.6 times (Cl, 1.3 to 33.1) as high in persons with gallstone disease as in those with normal gallbladders. Of the 20 fatal malignancies in persons with gallstone disease, 11 occurred in the digestive tract, of which six involved the gallbladder or bile ducts.

CONCLUSIONS

Increased cancer mortality and total mortality were found in Pima Indians with gallstone disease. Although plausible explanations exist for the increased cancer mortality, the increased death rates due to other causes are unexplained. Whether cholecystectomy would change this risk is unknown.

Epidemiology of alimentary cancers in New South Wales, 1973-82

Incidence and mortality data from New South Wales (NSW) for 1973-82 were examined using log-linear regression to determine the temporal trends of cancers of the alimentary tract. There were significant increases in incidence of cancers of the colon (1.7%/year), rectum (2.6%/year), and liver (4.0%/year) and decreases for cancers of the oesophagus (-2.2%/year) and stomach (-1.4%/year). By contrast, the mortality decreased significantly for cancers of the colon (-1.0%/year) and pancreas (-1.4%/year) as well as for cancers of the oesophagus (-3.4%/year) and stomach (-4.1%/year). Cancers of the colon, rectum and oesophagus were generally less frequent, and cancer of the stomach was more frequent, among migrants to NSW than among the native-born Australians in NSW. This pattern was most evident in migrants from Greece, Italy, Yugoslavia and England and was absent in migrants from Scotland and New Zealand. When compared with the state as a whole, rural NSW had significantly lower incidences of cancers of the oesophagus, stomach, colon and rectum.